Prolactin (PRL), also known as lactogen, is secreted by the pituitary gland. The diagnostic criteria for hyperprolactinemia is a blood test for prolactin ≥ 25ng/ml (or 530mIU/L). The conversion factor between these two units is: ng/mL x 21.2 = mIU/L. Generally, prolactin ≥ 100 ng/ml (or 2120 mIU/L) requires MRI or CT of the pituitary gland to see if there is a pituitary tumor. There are many factors that can significantly increase prolactin, such as: pregnancy (including post-abortion), lactation, high protein diet, exercise, mental stress, sexual intercourse, stimulation of nipples or chest, medical and surgical diseases (renal insufficiency, chest wall trauma or surgery, etc.), hypoglycemia, taking sleeping pills, psychiatric drugs, drugs for stomach problems (antacids, antiemetics), birth control pills, antihypertensive drugs (reserpine, methyldopa, etc.), etc. Therefore, attention should be paid to the diagnosis of hyperprolactinemia to exclude the influence of these factors and avoid misdiagnosis.
The incidence of hyperprolactinemia has increased significantly in recent years. Most patients have an unknown cause (idiopathic), a few have pituitary microadenomas (<1 cm in diameter), pituitary macroadenomas (>1 cm in diameter) are rare, and other intracranial tumors are very rare. The common risks of hyperprolactinemia are threefold: first, infertility due to amenorrhea or scanty menstruation, including miscarriage due to marked increase in prolactin during pregnancy; second, genital atrophy, decreased libido and sexual difficulties due to suppression of ovarian function; and third, endometrial lesions (precancerous or even cancerous) due to long-term amenorrhea. Therefore, hyperprolactinemia should be treated actively. So, is it necessary to continue taking the medication after pregnancy? Is bromocriptine safe for the fetus and newborn during pregnancy and breastfeeding?
1. Should bromocriptine be discontinued immediately after pregnancy in hyperprolactinemic patients?
If the pre-pregnancy prolactin is not too high (<50 ng/ml or 1060 mIU/L), especially if the prolactin has dropped to normal after a long period of oral treatment (e.g. more than half a year) and the pregnancy has been stable for a period of time, bromocriptine can be discontinued as soon as pregnancy is confirmed.
Although the pre-pregnancy prolactin is not too high, but not after a period of strict treatment, or cannot tolerate the side effects of bromocriptine without taking the medication regularly, or the treatment of resistance to bromocriptine is not effective, the prolactin is still high before pregnancy, because high prolactin can lead to luteal insufficiency, which may cause the risk of miscarriage, it is best to continue to apply bromocriptine treatment in the early 3 months of pregnancy, especially for those who have had high prolactin before. It is advisable to continue bromocriptine treatment during the early trimester, especially for pregnant women with a previous history of spontaneous abortion in early pregnancy due to hyperprolactinemia, in order to prevent miscarriage. The dose of bromocriptine can be reduced during pregnancy (e.g. by half the dose), keeping the blood PRL at the corresponding normal or slightly higher level during pregnancy, i.e. the lowest effective dose is taken continuously.
Bromocriptine is safe to be used during pregnancy. The FDA (U.S. Food and Drug Administration) drug pregnancy classification of bromocriptine is B (i.e. no adverse effects on the fetus have been seen in studies, penicillin is B), which is also confirmed by a large number of clinical observations, so the application of bromocriptine during pregnancy has no adverse effects on the embryo or does not cause fetal malformation, and can be used without worry. However, we should pay attention to the side effects of the drug and early pregnancy reactions, such as nausea, dizziness, drowsiness, etc. If the reactions are particularly severe, we can stop the drug first for observation.
2.Will the pituitary tumor grow during pregnancy for patients with pituitary tumor? If the pituitary tumor grows, do I need to resume the medication?
Generally, pituitary microadenoma (<1cm in diameter) will not aggravate during pregnancy, while macroadenoma (>1cm in diameter) has a high risk of aggravation during pregnancy, so patients with macroadenoma should actively treat it before pregnancy and get pregnant after it has significantly improved. Regardless of microadenoma or treated macroadenoma, it is important to self-monitor the pituitary tumor after pregnancy for self-perceived symptoms such as headache, vision changes and other neurological symptoms. When these symptoms are present, a pituitary magnetic resonance imaging (MRI) can be done (note that only MRI can be done, not CT, as the latter has X-rays which are not good for the fetus) to see if the pituitary tumor has increased significantly. Even if there are no symptoms, visual field and vision examinations should be performed in the early, middle and late stages of pregnancy.
If there are neurological symptoms, or if the pituitary tumor pituitary tumor increases in size, or if prolactin rises rapidly compared to normal pregnancy, treatment with oral bromocriptine should be started immediately.
In normal pregnancy, prolactin rises gradually, with blood PRL <80ng/ml in the early 3 months of pregnancy; blood PRL <160ng/ml in the middle 3 months of pregnancy; and blood PRL <400ng/ml in the late 3 months of pregnancy.
3.What indicators should be monitored during pregnancy medication? What criteria can patients taking medication during pregnancy reach to stop the medication?
It is necessary to monitor whether the treatment effect is good after taking the medication during pregnancy. It is mainly monitored from the following aspects.
(1) Self-monitoring of neurological symptoms of pituitary tumors, such as headaches and changes in vision.
(2) Visual field and vision examinations when there are neurological some symptoms, or even if there are no symptoms in the early, middle and late stages of pregnancy.
(3) Magnetic resonance imaging (MRI) of the pituitary gland, if necessary, to see if the pituitary tumor is significantly enlarged.
(4) Regular (e.g., once a month) blood tests for prolactin to see if it is significantly higher than normal for pregnancy.
In pregnant women with poorly controlled hyperprolactinemia, continued treatment with bromocriptine is recommended in the early trimester to prevent miscarriage; in the middle and late trimester when the risk of miscarriage is significantly reduced, if the monitoring of PRL is normal or only mildly elevated, discontinuation of the drug for observation can be considered. For microadenoma, after taking the drug treatment, if the self-conscious symptoms have disappeared for a period of time (>1 month), the visual field and vision examination are normal, the MRI pituitary tumor is not significantly enlarged, and the blood PRL has dropped to within the normal range of the corresponding stage of normal pregnancy for a period of time (>1 month), the drug can be considered to be discontinued, but regular monitoring of the above indicators is still required. For macroadenoma, it is recommended to adhere to the medication throughout pregnancy until the end of the puerperium (after 42 days postpartum), when the blood PRL drops to normal, and then consider stopping the medication for observation.
4.What is the need to continue taking medication after delivery if I did not take medication during pregnancy?
If you did not take any medication during pregnancy and your condition is stable, it means that your condition is relatively mild. However, if prolactin is significantly elevated again after delivery, or if pituitary tumors (even if they are microadenomas) are found, you should continue to take medication.
5.Can a woman taking the drug breastfeed?
Bromocriptine does not affect breastfeeding. It has no adverse effects on the fetus and is safe for the baby, so mothers taking the drug can breastfeed.